Cross flow fan

ABSTRACT

A cross flow fan mainly includes an enclosure, a cross fan and a motor. When the cross fan rotates by the motor, air is drawn into the cross flow fan through the intake hole and then is exhausted through the ventilating hole. The device is characterized in that the ventilating hole and the intake hole is located on the position of 0 degree and 180 degrees respectively and the end point of the arched wind fending board is located on the range from 70 to 150 degrees. The wind fending board installed between the intake hole and the ventilating hole is arched in an radian a bit larger than that of the fringe of the cross fan so as to have better ventilating efficiency.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a cross flow fan, especially to a kind of fan that the ventilatory amount of air is efficiently increased.

[0003] 2. Description of the Prior Art

[0004] A conventional cross flow fan is composed of an enclosure, a fan and a motor. The ventilating amount of air depends on the design related to position of the ventilating hole and position of the aspirating hole. Refer from FIG. 4 to FIG. 7, structure of several common types of cross flow fans mainly comprising an enclosure (a), cross fan (b) and a motor (c) (shown in dotted line). An intake hole (a1) and a ventilating hole (a2) are disposed on the enclosure (a) respectively. On the top side of the intake hole (a1) and the ventilating hole (a2) is a wind fending board (a3) while a wind guiding plate (a4) is arranged on the bottom side thereof. When the cross fan (b) is driven by the motor(c), the air is taken through the intake hole (a1) and then is exhausted by the ventilating hole (a2) so as to achieve the function of heat dissipation.

[0005] In above prior arts, the intake hole (a1) conventional fan is generally quite large in order to increase the efficiency of the air ventilation. The end point (a31) of the wind fending board (a3) on the top of the intake hole (a1) is arranged adjacent to the end of (a32) of the wind fending board (a3) on the top of the ventilating hole (a2). If the horizontal line of the rotating axis of the cross fan (b) is zero degree while the perpendicular line of the rotating axis of the cross fan (b) is 90 degrees, the position of the end point (a31) of the wind fending board (a3) on the top of the intake hole (a1) falls on the range from 40 to 50 degrees. Thus the range for air intake hole is quite large and the position of the intake hole (a1) is too close to the position of the ventilating hole (a2). Also the distance between the wind fending board (a3) on the top of the ventilating hole (a2) and the cross fan (b) is quite large. Therefore, the air flow exhausted by the ventilating hole (a2) is easy to be drawn back to the position of the intake hole (a1) and caused interference current so that the intake of the air and the ventilatory efficiency are influenced.

[0006] Moreover, refer from FIG. 4 to FIG. 7, the intake hole (a1) includes a main air intake area on the top side thereof which takes 70% amount of the total air intake and a minor air intake area on the lateral side thereof which takes 25% amount of the total air intake. Once the height of the place for accommodating the device is limited and the main air intake area on the top side of the device is covered by the enclosure of the equipment, the amount of air intake is reduced up to 50%. There are also other disadvantages such as small amount of air ventilation and a lot noises. Thus there is a need to improve the design of conventional cross flow fans, especially the enclosure that part.

SUMMARY OF THE INVENTION

[0007] It is therefore a primary object of the present invention to provide a cross flow fan with special design of wind fending board on the top side between the intake hole and the ventilating hole so as to reduce the amount of the air drawn back for improving the efficiency of air ventilation.

[0008] It is a further object of the present invention to provide a cross flow fan wherein the intake hole and the ventilating hole is located on the position of 180 degree and 0 degrees in linear respectively so that the intake hole of the present invention will not be covered by the top plate of the enclosure of the equipment when the present invention is installed inside smaller equipment with lower height. Therefore the amount and efficiency of air intake will not be influenced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accomplishment of the above-mentioned object of the present invention will become apparent from the following description and its accompanying drawings which disclose illustrative an embodiment of the present invention, and are as follows:

[0010]FIG. 1 is an explosive view of a cross flow fan in accordance with the present invention;

[0011]FIG. 2 is a perspective view of the present invention;

[0012] FIGS. 3A-3C shows cross sectional views of three embodiments of a wind fending board of the present invention;

[0013]FIG. 4 is a cross sectional view of an embodiment of a prior art;

[0014]FIG. 5 is a cross sectional view of another embodiment of a prior art;

[0015]FIG. 6 is a cross sectional view of a further embodiment of a prior art;

[0016]FIG. 7 is a cross sectional view of still a further embodiment of a prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] Refer from FIG. 1 to FIG. 3, the cross flow fan mainly includes an enclosure (10), a cross fan (20) and a motor (30). Outside blades of the cross fan (20), an intake hole (11) and a ventilating hole (12) are installed on the enclosure (10). On the top side of the intake hole (11) and the ventilating hole (12), a wind fending board (13) is formed as a part of the enclosure 10 while a wind guiding plate (14) is arranged on the bottom side thereof. When the motors rotate the fan (20), air is drawn into the enclosure 10 through the intake hole (11) and then is blown out through the ventilating hole (12).

[0018] The feature of the present invention is that when the vertical line of the rotating axis of the cross fan (20) is on the position of 90 degrees, the ventilating hole (12) and the intake hole (11) is located on the position of 0 degree and 180 degrees respectively. The end point of the arched wind fending board (131) is located on the range from 70 to 150 degrees. The wind fending board (13) arranged between the intake hole (11) and the ventilating hole (12) is arched in an radian a bit larger than that of the fringe of the cross fan (20).

[0019] In accordance with the structure mentioned above, the arched wind fending board (13) with the end point (131) extending backwards is quite close to the fringe of the cross fan (20) and there is a certain distance between the intake hole (11) and the ventilating hole (12) thus the wind fending board (13) can prevent the air flow near the ventilating hole (12) from being drawn back to the intake hole (11). There is no more interference current produced nearby the intake hole (11). Therefore, the inner side air pressure of the intake hole (11) is reduced thus a large amount of air is drawn into the device through the intake hole (11). Moreover, the arched wind fending board (13) above the ventilating hole (12) can efficiently prevent the air flow being drawn back to the intake hole (11). The design of the present invention has the best efficiency of air intake and ventilation.

[0020] Refer to embodiments shown in the FIGS. 3A-3C, the intake hole (11) and the ventilating hole (12) is located on the position of 180 degree and 0 degrees respectively so that the pathway of air flow is linear. Thus the intake hole (11) of the present invention will not be covered by the top plate of the enclosure of the equipment when the present invention is installed inside smaller equipment with lower height. Thus the amount of air intake will not be influenced.

[0021] It should be noted that the above description and accompanying drawings are only used to illustrated some embodiments of the present invention, not intended to limit the scope thereof. Any modification of the embodiments should fall within the scope of the present invention. 

What is claimed is:
 1. A cross flow fan comprising an enclosure having an intake hole, a ventilating hole, a wind fending board and a wind guiding plate, a cross fan, and a motor, wherein said intake hole and said ventilation hole are disposed on said enclosure, the position outside the blades of said cross fan; said wind fending board is located on the top side of said intake hole and said ventilating hole while said wind guiding plate is arranged on the bottom side thereof; when said cross fan rotates by said motor, air is drawn into the cross flow fan through said intake hole and then is exhausted through said ventilating hole; the improvement of the present invention is characterized in that when the vertical line of the rotating axis of said cross fan is on the position of 90 degrees, said ventilating hole and said intake hole is located on the position of 0 degree and 180 degrees respectively and the end point of said arched wind fending board is located on the range from 70 to 150 degrees; said wind fending board arranged between said intake hole and said ventilating hole is arched in an radian a bit larger than that of the fringe of said cross fan. 